This invention relates to a stud welding gun for welding studs of different lengths to base members and a method of using the stud welding gun.
The present invention relates to a new and improved stud welding gun which is used to weld studs to a base member.
Stud welding guns have previously been utilized to weld studs to a base member. The studs are welded to the base member by establishing an electrical arc between the stud and the base member to heat the metal at the tip of the stud and the base member to a molten or liquid state and then plunging the stud into the base member before the molten metal cools to solid state.
Stud welding guns have been utilized which incorporate a feed system to automatically feed the studs to the gun for quick sequential welding of studs. Stud welding guns have also been developed which can accommodate studs of varying lengths.
However, previous designs require that the gun be adapted in some way to accommodate the studs when switching from one length to another, as well as to accommodate the delivery system for the various lengths of studs. Typically the modifications necessary to allow the gun to switch from one length of stud to another are time consuming and involve interchanging various parts.
A stud welding gun for use in alternatively welding studs of a first length and a second length to base members. The stud welding gun comprises a handle assembly, and a frame which is connected with and extends outward from the handle assembly. The gun includes a stud holder disposed at an outer end portion of the frame to hold a stud while an electrical current flows between the stud and the base member during welding. The gun also includes a stud feed member and a housing that are connected with the frame. The stud feed member is movable from a retracted position to an extended position to move a stud toward the stud holder. The gun further includes at least two stud cartridges each having a plurality of studs. Each cartridge has opposed first and second side walls to receive a plurality of studs in side by side array and opposed end walls extending between the first and second side walls. A first cartridge has end walls spaced a distance approximately equal to the first length to receive studs having the first length. A second cartridge has end walls spaced a distance approximately equal to the second length to receive studs having the second length. At least one of the side walls of each of the cartridges extends beyond the end walls to a pre-determined overall length, each of the cartridges having said pre-determined overall length. The housing is adapted to receive cartridges of the pre-determined overall length, with a longitudinal central axis of each stud of the plurality of studs extending along the path of movement of the stud feed member between the extended and retracted positions. The gun includes a stud mover that sequentially moves studs in the plurality of studs into the path of movement of the stud feed member between the extended and retracted positions.
The stud welding gun of the present invention provides the advantage of including cartridges for delivering varying lengths of studs to the gun. The cartridges each have the same overall length, thereby making it possible to remove a first cartridge with studs of a first length from the gun and replace the first cartridge with a second cartridge of studs having a second length without having to make any modifications to the gun to accommodate the second cartridge. As used herein, the term xe2x80x9clengthxe2x80x9d refers to the distance between opposing ends of the side walls of the cartridge. This feature and other features of the present invention provide a stud welding gun that can effectively be used to weld studs of different lengths while allowing the operator of the gun to change over from studs of a first length to studs of a second length quickly and easily.